The present invention relates to a showcase in which a display chamber is disposed inside an insulating wall so as to display commodities while cooling the commodities in the display chamber. More particularly, it relates to illumination in the display chamber.
In a showcase heretofore installed in a supermarket, a convenience store or the like, illumination lamps for illuminating the inside of a display chamber, the front part of the showcase and the like are attached in the display chamber formed in a main body (e.g., see JP-A-5-146346). The illumination lamps are attached to the lower surface of a canopy positioned in the front part of the ceiling surface of the display chamber, and the front parts of the lower surfaces of a plurality of shelves in a case where the shelves are provided. As the illumination lamps, fluorescent lamps and the like are usually used, but the lamps have to be replaced owing to the lowering of luminance due to deterioration with an elapse of time, or lighting defect. Moreover, the fluorescent lamps use an alternate current, and hence flicker, which adversely influences eyes.
To solve the problem, heretofore, a showcase has been developed which employs an LED illumination apparatus comprising a plurality of LED elements as an illumination apparatus, thereby illuminating the inside of the display chamber.
Such an LED illumination apparatus comprises a substrate provided with the plurality of LED elements, a heat radiation member, a reflective plate, a shade positioned on the side of at least the light emitting surfaces of the LED elements, an attachment member and the like. The LED elements have a high directivity, and the irradiation angles of the elements can arbitrarily be changed, whereby an illumination effect in the display chamber can be improved.
As a constitution in which the irradiation angle of light by the LED illumination apparatus can arbitrarily be changed, there is suggested a constitution in which the angle of the attachment member attached on a showcase side can arbitrarily be regulated, or a constitution in which the LED illumination apparatus can be held at a predetermined angle by an engaging member such as a holder (e.g., a clip constituted of a pair of leg portions having elasticity) attached on the showcase side.
However, in the case of the employment of the attachment member which is attached on the showcase side and whose angle itself can arbitrarily be regulated, the constitution becomes complicated, which causes problems such as the increase of the number of components, the lowering of productivity, and cost increase.
Moreover, in the constitution in which the LED illumination apparatus is held by the holder attached on the showcase side, for example, an LED illumination apparatus 100 shown in FIG. 11 is employed. The LED illumination apparatus 100 is constituted of a substrate 102 provided with a plurality of LED elements 101 arranged in a longitudinal direction, a fixing member 103 for fixing the substrate 102, and a shade 104 provided with the fixing member 103 and configured to surround the LED elements 101, the substrate 102, the fixing member 103 and the like.
In this case, the shade 104 has a substantially semi-cylindrical section including an arc-like section on the side of the light emitting surfaces of the LED elements 101. In consequence, an engaging member such as the holder nips a pair of corner portions 105, 105 where the arc and chord of the substantially semicircular section intersect with each other, thereby detachably holding the LED illumination apparatus 100, but the member has the substantially semicircular shape, and the angles of the corner portions 105 are as large as about 90°, which causes a problem that it is difficult to stably nip and hold the apparatus by the engaging member.
To solve the problem, it is suggested that the corner portions 105 be simply formed into a shape having an acute angle, but in this case, corners are formed in the shade 104 on the side of the light emitting surfaces of the LED elements, and lines due to the corners are formed in the irradiation light from the LED elements 101, which causes a problem that appropriate illumination cannot be realized.
The present invention has been developed to solve such conventional technical problems, and an object thereof is to provide a showcase comprising an illumination apparatus which can stably be held by a simple structure and which can illuminate the inside of a display chamber effectively without any unevenness.